When to disconnect autopilot on approach

[Killaroo]

A certain gent recently opined it was good airmanship to not disconnect the AP until in receipt of landing clearance. I've never heard of such tosh in my life before- but maybe I've spent 30 years flying in ignorance.
What say ye?

[ahramin]

Pretty simple really. 1 out of 10 go-arounds leads to an unsafe situation, often due to non-existent manual flying skills.

So if you are an adherent to the "autopilot always on" school of thought and have trouble manually flying a go-around, airmanship would indeed dictate that you leave the autopilot on until cleared to land to reduce the risk of a botched go-around.

While I haven't seen a memo or SOP on this at my company yet, many instructors are already preaching this for landings at LGW because of the high number of GAs there. I think it's only a matter of time before this becomes part of many airline's SOPs.

[Dash8driver1312]

I can understand the logic-well done on being so preachily close-minded and degrading in your rapid dismissal-but I do prefer to keep my hand in with manual flying.

I wonder how this person deals with situations when a tower advises to expect a landing clearance that may come after the MDA, or circling approaches?

You might find life better to try open discourse instead of kicking off on such an aggressive footing...good luck on your next CRM course!

[flarepilot]

will someone tell me what "TOSH" is ?


we had ways of remembering landing clearance, but the best one and seemed most agreed upon was cleared to land, turn nose taxi/landing light on.

but we were and still are men and autopilots were and are for those who need them. (ops specs aside)

[Piltdown Man]

Yes, it's tosh! Minimum A/P disconnection heights/altitudes are normally specified in AOMs, maximums are not specified. Therefore, disconnection should take place between cruise altitude and the minimum specified for the approach - a mixture of common sense and personal preference dictating exactly when. But when you next speak with said gent, you may wish to tell him that poor airmanship is restricting A/P disconnection until you are cleared to land.

[GA_flps1]

On the 737ng boeing recommends 2-3nm out.

I prefer having the autopilot connected until the runway is clear, without the autopilot we're not allowed to use the A/T, and without the A/T I will have to set the GA thrust manually, why do more work than I get paid for? :E

[172_driver]

On the 737ng boeing recommends 2-3nm out.

Where is that recommended?

[GA_flps1]

Woops wrong should have been 1 to 2nm

FCTM rev11

When a manual landing is planned from an approach with the autopilot
connected, the transition to manual flight should be planned early enough
to allow the pilot time to establish airplane control before beginning the
flare. The PF should consider disengaging the autopilot and disconnecting
the autothrottle 1 to 2 nm before the threshold, or approximately 300 to 600
feet above field elevation.

[galaxy flyer]

Reading this thread makes one wonder where in the heck piloting got to ths low state. Really, do we need an SOP and AOM guidance on flying the plane and use of the autopilot? Then, we have threads on lack of proficiency and low compensation. Well, there's your problem right there--if you require management guidance on basic flying (landing and go-arounds); don't expect much improvement.

[172_driver]

GA_flps1,

Thanks, did not know such a recommendation existed that it was just another pilot's opinion.. :O

[de facto]

I am with galaxy flyer on that one.
And to the OP,yes its utter tosh.

[Jwscud]

Seems most of us ignore the FCTM then.

On a nice day at home base, it normally comes out at just before configuring. If it's miserable, leave it until youre stable and visual. Surely it's just a matter of common sense and airmanship?

[Lord Spandex Masher]

Not really. "Should consider" isn't the same as 'must'.

Mind if I hand fly boss?

Do what you like, just don't do anything illegal or dangerous and don't crash.

[Jwscud]

Indeed, though the way I read that FCTM excerpt is that it considers that 5-600' is EARLY.

It seems to be a bit of legalistic stuff to avoid MINIMUMS *click click* oh sh*t crunch rather than genuine advice on how to fly the aircraft. One or two of my colleagues have much earlier revisions of the FCTM which contain a lot more sensible stuff that seems to have been excised by the lawyers.

[Killaroo]

Yes I do understand that at certain busy airports with complex Go Arounds it might make it simpler for the Children Of The Megenta Line to keep the Autopilot engaged until 'assured' landing is likely. Heck, why not just do an Autoland anyhow.
But, in truth, if I have to GA with the autopilot disengaged its not all that hard. Throttles up to TOGA, point it skyward, call FLAP, and GEAR UP.
Then you can reach over, push the AP PB and push heading for NAV.
Really tricky, eh?

[con-pilot]

With me back when I was flying, 10,000 feet. Regardless of the type of approach.

But I'm from the old school of thinking, using the auto-pilot as an aid, not the primary operator of the flight contols for approachs and landings.

[JeroenC]

On the NG single channel, the AP disconnects on GA....
Setting GA is done by PM, let him have some work!

[DooblerChina]

LGW = 500'
MAN = base leg
Greek Island on a visual = 20000'+

Do whatever's comfortable, safe and sensible is the point I'm really trying to make...

[High Energy]

I was actually thinking of this the other day and started to make a note of when I typically disconnect the autopilot and found it's between 1200-1000ft. So basically after my personal 'stable gate', even in VMC.

Also, in the last 6 months I have not come across one colleague who disconnected what some concieve as early, ie between FL100-3000ft. In the month prior to that I had one colleague who disconnected it at Fl150 to save the approach as it would have been bloody hard work to manage it with the a/p engaged. (ex bush pilot for what it's worth and he did a stunning job)

I do fly all my departures manually up to FL100 and are new to type/manufacturer.

A lot of the times, IMHO, you also benefit more from utilizing your a/p, a/t and situational awareness skills than from the manual handling part due to a challenging ATC or terrain enviroments. No mention of wx for obvious reasons.

[Tu.114]

Horses for courses.

Of course, in marginal weather or with otherwise high workload, it is good practice to dump as much work on the computers as one possibly can. But with everything else in order, I do not hear "airmanship" call me to just observe the computers do what is in essence my job. Even more so as my type tends to restrict the use of the Autopilot in case of technical malfunctions: a single engine approach must be flown manually for example. So with non-critical visibility and ceiling, I consider it well advisable to use the opportunity for some hand flying as often as practical just to keep the skills ready and alive. In nice weather, I tend to switch the A/P and occasionally, situation permitting, as well the F/D off at 3000 to 6000ft.

As has been mentioned, the automatics are there to help and keep the workload at bay. They are not installed to substitute the pilots or to allow them to let their skills erode. I would therefore define airmanship with regards to automatics as "knowing how and when to use the systems capabilities while keeping ones personal skills honed".

[Centaurus]

and without the A/T I will have to set the GA thrust manually

OMG! Manual thrust. What a frightening experience. Would that be a Mayday or will a PAN PAN cut it?:D

[Tu.114]

Just for reference - is the A/T releasable under MEL on Your type?

[Jwscud]

I flew a few 4 sector days a week or two back with no AT (737).

Only restriction is CAT I only. Good excuse for a bit more hand flying.

[172_driver]

From a FO's perspective,

At my base hand flying is encouraged by the majority of my colleagues in the LHS. No excuses needed, I disconnect normally around FL100-150. IMC as well as long as it's just clouds, no CB or weather needing extra attention. I enjoy it for the fun of it. I know many will disagree but the vast SOPs these day kill pretty much every freedom there used to be in flying. It's not a breach of SOP, and I am simply doing what the AP & AT would otherwise do.

I also do it because I am trained & paid to be a pilot, it's an art I'd like to see being kept alive. Manual flying on the line gives a good foundation of flying skills the TR did not provide. When I did my ATPL ride, the TRE told me the day before he had to fail another applicant. He gave him three (3) shots at a raw data ILS from intercept heading. He just couldn't do it. He's still on the line and probably many like him..

[172_driver]

Was jumpseating the other day when the A/P disconnected in climb out due to intermittent SPD LIMIT FLAG. The PF was obviously caught off gaurd, hands all over the MCP.. LVL CHG.. nothing happens, dials in low V/S. Speed is slowly decaying towards up speed and I can't help but finally saying from where I am sat "the autopilot is off".. as you might have guessed A/P disconnect horn kept singing throughout the rather messy recovery. At the end of the flight the A/P finally came out at 500 ft fully configured on a beautiful SKC day destination.

[DooblerChina]

172 driver,

What airline do you fly for? I would quite like to avoid them.

[172_driver]

There are many reasons to avoid them..

But I am afraid this is not limited to one airline..